Most cited article - PubMed ID 33926097
Ovariectomy-Induced Hepatic Lipid and Cytochrome P450 Dysmetabolism Precedes Serum Dyslipidemia
Metabolic syndrome (MetS) is a cluster of risk factors that increase the likelihood of developing cardiovascular, metabolic and other diseases. The pharmacological management of MetS often involves polypharmacy, making it essential to understand how drug-metabolising enzymes, transporters, transcription factors and other proteins involved are affected under different metabolic conditions. This study investigated the relative mRNA expression of key hepatic and intestinal genes involved in drug metabolism, including Cyp1a2, Cyp3a23, Cyp2d1, Cyp2c11, Cyp2c6, Cyp2e1, Cyp7a1, Cyp2b1, Cyp2a1, Abcg5, Abcg8, Abcb1, Nr1i3, Nr1i2, Ahr, Gsta1 and Comt, in four nonobese rat models of MetS: hereditary hypertriglyceridaemic (HHTg), spontaneously hypertensive rat (SHR), SHR expressing transgenic human C-reactive protein (SHR-CRP), and bilaterally ovariectomised Wistar (W-OVX), compared to Wistar controls. Gene expression was quantified by RT-PCR with data normalised using the ΔΔCt method. Between the models studied, measurements showed significant differences in the liver. The upregulation of Cyp2c6 and Cyp3a23 was observed only in SHR; upregulated Cyp2d1 was found in SHR as well as in HHTg rats. The downregulated Cyp1a2 was measured in a condition of hypertriglyceridemia, postmenopause or hypertension. These findings highlight model-specific alterations in gene expression that may affect drug metabolism and interactions. The HHTg may be, in particular, a suitable model for preclinical studies focusing on intestinal drug-drug interactions in MetS-related conditions.
- Keywords
- drug metabolism, metabolic syndrome, rat model,
- MeSH
- Liver metabolism enzymology MeSH
- Rats MeSH
- Humans MeSH
- Membrane Transport Proteins * genetics metabolism MeSH
- RNA, Messenger * metabolism genetics MeSH
- Metabolic Syndrome * genetics metabolism MeSH
- Disease Models, Animal MeSH
- Rats, Inbred SHR MeSH
- Rats, Wistar MeSH
- Receptors, Cytoplasmic and Nuclear * genetics metabolism MeSH
- Cytochrome P-450 Enzyme System * genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Membrane Transport Proteins * MeSH
- RNA, Messenger * MeSH
- Receptors, Cytoplasmic and Nuclear * MeSH
- Cytochrome P-450 Enzyme System * MeSH
Menopause brings about profound physiological changes, including the acceleration of insulin resistance and other abnormalities, in which adipose tissue can play a significant role. This study analyzed the effect of ovariectomy and estradiol substitution on the metabolic parameters and transcriptomic profile of adipose tissue in prediabetic females of hereditary hypertriglyceridemic rats (HHTgs). The HHTgs underwent ovariectomy (OVX) or sham surgery (SHAM), and half of the OVX group received 17β-estradiol (OVX+E2) post-surgery. Ovariectomy resulted in weight gain, an impaired glucose tolerance, ectopic triglyceride (TG) deposition, and insulin resistance exemplified by impaired glycogenesis and lipogenesis. Estradiol alleviated some of the disorders associated with ovariectomy; in particular, it improved insulin sensitivity and reduced TG deposition. A transcriptomic analysis of perimetrial adipose tissue revealed 809 differentially expressed transcripts in the OVX vs. SHAM groups, mostly pertaining to the regulation of lipid and glucose metabolism, and oxidative stress. Estradiol substitution affected 1049 transcripts with overrepresentation in the signaling pathways of lipid metabolism. The principal component and hierarchical clustering analyses of transcriptome shifts corroborated the metabolic data, showing a closer resemblance between the OVX+E2 and SHAM groups compared to the OVX group. Changes in the adipose tissue transcriptome may contribute to metabolic abnormalities accompanying ovariectomy-induced menopause in HHTg females. Estradiol substitution may partially mitigate some of these disorders.
- Keywords
- estradiol substitution, hereditary hypertriglyceridemic rat, insulin sensitivity, ovariectomy, perimetrial adipose tissue, transcriptomics,
- Publication type
- Journal Article MeSH
Background and aims: Low-grade chronic inflammation plays an important role in the pathogenesis of metabolic syndrome, type 2 diabetes and their complications. In this study, we investigated the effects of salsalate, a non-steroidal anti-inflammatory drug, on metabolic disturbances in an animal model of prediabetes-a strain of non-obese hereditary hypertriglyceridemic (HHTg) rats. Materials and Methods: Adult male HHTg and Wistar control rats were fed a standard diet without or with salsalate delivering a daily dose of 200 mg/kg of body weight for 6 weeks. Tissue sensitivity to insulin action was measured ex vivo according to basal and insulin-stimulated 14C-U-glucose incorporation into muscle glycogen or adipose tissue lipids. The concentration of methylglyoxal and glutathione was determined using the HPLC-method. Gene expression was measured by quantitative RT-PCR. Results: Salsalate treatment of HHTg rats when compared to their untreated controls was associated with significant amelioration of inflammation, dyslipidemia and insulin resistance. Specificaly, salsalate treatment was associated with reduced inflammation, oxidative and dicarbonyl stress when inflammatory markers, lipoperoxidation products and methylglyoxal levels were significantly decreased in serum and tissues. In addition, salsalate ameliorated glycaemia and reduced serum lipid concentrations. Insulin sensitivity in visceral adipose tissue and skeletal muscle was significantly increased after salsalate administration. Further, salsalate markedly reduced hepatic lipid accumulation (triglycerides -29% and cholesterol -14%). Hypolipidemic effects of salsalate were associated with differential expression of genes coding for enzymes and transcription factors involved in lipid synthesis (Fas, Hmgcr), oxidation (Pparα) and transport (Ldlr, Abc transporters), as well as changes in gene expression of cytochrome P450 proteins, in particular decreased Cyp7a and increased Cyp4a isoforms. Conclusion: These results demonstrate important anti-inflammatory and anti-oxidative effects of salsalate that were associated with reduced dyslipidemia and insulin resistance in HHTg rats. Hypolipidemic effects of salsalate were associated with differential expression of genes regulating lipid metabolism in the liver. These results suggest potential beneficial use of salsalate in prediabetic patients with NAFLD symptoms.
- Keywords
- cytochrome P450, lipid metabolism, low-grade inflammation, oxidative stress, prediabetes, salsalate,
- Publication type
- Journal Article MeSH
BACKGROUND: If menopause is really independent risk factor for cardiovascular disease is still under debate. We studied if ovariectomy in the model of insulin resistance causes cardiovascular changes, to what extent are these changes reversible by estradiol substitution and if they are accompanied by changes in other organs and tissues. METHODS: Hereditary hypertriglyceridemic female rats were divided into three groups: ovariectomized at 8th week (n = 6), ovariectomized with 17-β estradiol substitution (n = 6), and the sham group (n = 5). The strain of abdominal aorta measured by ultrasound, expression of vascular genes, weight and content of myocardium and also non-cardiac parameters were analyzed. RESULTS: After ovariectomy, the strain of abdominal aorta, expression of nitric oxide synthase in abdominal aorta, relative weight of myocardium and of the left ventricle and circulating interleukin-6 decreased; these changes were reversed by estradiol substitution. Interestingly, the content of triglycerides in myocardium did not change after ovariectomy, but significantly increased after estradiol substitution while adiposity index did not change after ovariectomy, but significantly decreased after estradiol substitution. CONCLUSION: Vascular and cardiac parameters under study differed in their response to ovariectomy and estradiol substitution. This indicates different effects of ovariectomy and estradiol on different cardiovascular but also extracardiac structures.
- Keywords
- cardiovascular changes, estradiol substitution, hereditary hypertriglyceridemic rat, insulin resistance, ovariectomy,
- MeSH
- Estradiol * MeSH
- Insulin Resistance * physiology MeSH
- Rats MeSH
- Humans MeSH
- Menopause metabolism MeSH
- Ovariectomy adverse effects MeSH
- Heart MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Estradiol * MeSH